Using creep and recovery to study flow behavior of fresh cement paste

✍ Scribed by Leslie J. Struble; Mark A. Schultz

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 584 KB
• Volume: 23
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(93)90074-j

✦ Synopsis

A controlled stress rheometer has been used to determine the creep and recovery behavior of flocculated cement pastes. The behavior was found to depend on the level of applied stress. At a lower applied stress, the creep curve of each paste was characteristic of a nonlinear viscoelastic solid, with an instantaneous strain superimposed on an elastic strain; the recovery, on the other hand, was characteristic of a viscoelastic liquid, with little or no instantaneous strain, but some retarded strain and a substantial unrecovered strain. At a higher applied stress the behavior was strikingly different. In this case, the behavior was characteristic of a viscous liquid, with a nearly linear increase in strain throughout the duration of the stress and no recovery when the stress was released. This transition from solid-like behavior to liquid-like behavior occurred over a very narrow stress increment, and the transition stress corresponded to the yield stress estimated from flow curves and from oscillatory shear measurements.